The invention relates to a memory cell and a nonvolatile memory array incorporating such a cell.
Nonvolatile memory arrays maintain their data even when power to the device is turned off. In one-time-programmable (OTP) arrays, each memory cell is formed in an initial unprogrammed state, and can be converted to a programmed state by an appropriate electrical pulse. This change is permanent, and such cells are not erasable. In other types of memories, the memory cells are erasable, and can be rewritten many times.
FIG. 1 illustrates a conventional memory cell. As shown in FIG. 1, a memory unit cell 2 is composed of a steering element 4, such as a diode, and a storage element 6 connected in series between a bit line 8 and a word line 10. Memory arrays in general, such as two-dimensional or three-dimensional arrays, may comprise many such memory cells arranged within the array.